Why do you freeze batch norm layer for fine-tuning?

[Seyoung9304]

Hi, this is a very nice work! Thanks for your contribution.

In your code, I found that you freeze every batch normalization layer when you finetune the model.

if args.stage != 'chairs':
        model.module.freeze_bn()

I wonder why you froze BN layer when you fine tune the model. Is there any theoretical or experimental reason for it?

Thank you in advance :)